Medical mattress with firmness adjustment

ABSTRACT

A mattress for institutional use provides upper and lower surfaces offering different levels of firmness through the use of gradiated firmness in multiple polymer foam layers.

CROSS REFERENCE TO RELATED APPLICATION

This application is a reissue of U.S. Pat. No. 9,877,591 issued on Jan.30, 2018 from U.S. patent application Ser. No. 14/018,946 filed Sep. 5,2013, which claims the benefit of U.S. provisional application61/707,540 filed Sep. 28, 2012 and hereby incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to mattresses providing pressureredistributing surfaces for medical or other use and in particular to amattress providing for two different mattress firmnesses.

Mattresses intended for hospitals or long-term care may provide for apressure redistribution layer intended to help reduce regions ofpressure that may lead to pressure ulcers. One method of providing apressure redistribution layer employs multiple layers of polyurethane orsimilar foam with the top layer that may be die cut or convoluted.Mattresses providing a pressure redistribution layer suitable formedical or institutional use will henceforth be termed “medicalmattresses”. Such mattresses are generally intended to be used witharticulating hospital or long-term care beds that allow the mattress tobe flexed by a bed mechanism to elevate or lower a head, foot, or middlesection.

Long-term care or hospital residents (henceforth patients) usuallycannot choose the firmness of their mattress. While some facilities maypurchase medical mattresses with different firmnesses, this approach isburdensome and expensive and does not allow for patient choice. Toaddress this problem, mattresses may be constructed of two layers ofpolymer foam, for example, a top layer of softer foam and a bottom layerof firmer foam. By flipping the mattress, a different layer is presentedat the upper surface of the mattress. Such mattresses may not providefor effective pressure redistribution necessary for reducing pressurepoints such as may cause localized blood circulation loss andulceration.

SUMMARY OF THE INVENTION

The present invention provides a medical mattress that may be flipped toexpose one of two different surfaces presenting different firmnesses.Improved pressure redistribution is obtained by multiple foam layersproviding a more gradual transition in firmness. In some embodiments, anonslip surface may be re-positionably attached on the lower surfacedepending on the mattress orientation to better hold the mattress inposition during bed articulation. In some embodiments, peripheral foamwalls (bolsters) may be re-positionably attached on the upper surfacedepending on the mattress orientation to help reduce the risk of patientfalls from the mattress. In some embodiments, one end of the mattressmay have opposed heel slopes to help reduce heel pressure regardless ofmattress orientation. While developed for medical use, the mattressclearly has utility in other settings including schools, homes andvehicles, and the invention is not limited to a particular market.

In one embodiment, the present invention provides a mattress having amattress body with opposed first and second supporting surfaces eachsized to receive and support a supine individual when the surface isupwardly facing and horizontal. The mattress body includes at leastthree polymer foam layers having different firmnesses and extendingalong substantial portions of the mattress length. A firmness of thepolymer foam layers is selected to present a lesser firmness to asupported individual lying on the first supporting surface than to thesupported individual lying on the second supporting surface. A coverfits around the mattress body to retain the mattress body therein.

It is thus a feature of at least one embodiment of the invention toprovide a single mattress that can offer different levels of firmnessfor different individuals and yet which provides for sufficient pressureredistribution to minimize pressure points for bedridden patients. Byemploying a gradiated structure of multiple foam layers, a trade-offbetween reducing point pressure and increasing broad area support can bemanaged.

A first polymer foam layer adjacent to the first supporting surface mayhave a lesser indentation force deflection (IFD) than the polymer foamlayer adjacent to the second supporting surface. A third polymer foamlayer positioned between the first and second polymer foam layers mayhave an IFD greater than the IFD of the first polymer foam layer and thesecond polymer foam layer.

It is thus a feature of at least one embodiment of the invention toprovide a firm center core layer improving broad area support to boththe soft and firm face while still allowing different firmnesses on thedifferent faces.

The mattress may include a fourth polymer foam layer positioned betweenthe first and third polymer foam layers having a greater IFD than thefirst polymer foam layer and a lesser IFD than the third polymer foamlayer.

It is thus a feature of at least one embodiment of the invention toprovide a graduated change in firmness of the foam layers to betteraccommodate the competing desires of different firmnesses and isolationof the different firmnesses on the single mattress.

The different polymer foam layers extending along at least a portion ofthe first and second supporting surface may exclude a foot portionadapted to support feet of a supine individual. A foot region polymerfoam element may extend along the mattress length in the foot portionhaving firmness no more than the least firmness of the different polymerfoam layers outside of the foot portion.

It is thus a feature of at least one embodiment of the invention toprovide improved foot comfort by eliminating heel pressure points in areversible mattress.

The foot region polymer foam layer may have a uniform firmness.

It is thus a feature of at least one embodiment of the invention tosimplify the construction of the foot region of the mattress.

The foot region may provide a reduced mattress thickness tapering inwardto an end of the mattress.

It is thus a feature of at least one embodiment of the invention tofurther reduce pressure on the heel or foot by depressing the relativesurface height of the mattress in the heel region.

The mattress may include a second cover outside the first cover whereinthe second cover includes indicia indicating relative firmness of thefirst and second opposed surfaces.

It is thus a feature of at least one embodiment of the invention toguide users in orienting the mattress correctly for desired firmness.

The inner cover may include indicia indicating relative firmness of thefirst and second opposed surfaces.

It is thus a feature of at least one embodiment of the invention toallow the outer cover to be removed and reinstalled correctly.

The first and second opposed surfaces may be substantially planarwithout a convoluted surface.

It is thus a feature of at least one embodiment of the invention toprovide firmness variations that do not rely on complex surfacetreatment.

The mattress may include a bottom cover adjustable to be positioned overat least a portion of the bottom of the mattress when the mattress is ineither of two orientations with the opposed first or second supportingsurface uppermost, the bottom cover including outwardly exposedanti-slip material.

It is thus a feature of at least one embodiment of the invention toprovide a reversible mattress that nevertheless offers slip resistance.

The bottom cover may be permanently attached to a cover fullysurrounding the mattress at one edge of the bottom cover and releasablyattachable to the cover fully surrounding the mattress at an opposededge of the bottom cover.

It is thus a feature of at least one embodiment of the invention toprovide a simple method of changing the surface of slip resistancedepending on the orientation of the mattress with reduced risk of lossor omission of the slip resistant surfaces.

The bottom cover may be releasably attachable to a mattress cover withhook and loop fasteners.

It is thus a feature of at least one embodiment of the invention toprovide an attachment method consistent with commercial laundering ofthe cover material.

The mattress may include a top cover adjustable to be positioned over atleast a portion of the top of the mattress body when the mattress bodyis in either of two orientations with the opposed first or secondsupporting surface uppermost, the top cover providing upwardly extendingbolsters positionable at opposed left and right edges of the mattressbody.

It is thus a feature of at least one embodiment of the invention toprovide a reversible mattress that offers bolsters on its upper surface.

These particular objects and advantages may apply to only someembodiments falling within the claims and thus do not define the scopeof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified perspective view of an articulating hospital bedsuitable for hospital or institutional use;

FIG. 2 is a perspective view in partial cutaway of one embodiment of themattress of the present invention with the soft surface facing upwardshowing an internal layer configuration and a fragmentary perspectiveview of the same mattress rotated with the firm surface facing upward;

FIG. 3 is a fragmentary cross-section taken along lines 3-3 of FIG. 2showing multiple internal foam layers and outer covering materials ofthe present invention in one embodiment;

FIG. 4 is an exploded perspective view of the mattress of FIG. 2 and arepositionable bottom cover providing a nonskid surface when attached tothe mattress;

FIG. 5 is a figure similar to FIG. 4 showing an alternative embodimentwhere the nonskid surfaces are placed on straps fixedly attached to oneside of the mattress to be folded over or underneath the mattressdepending on mattress orientation to expose a nonskid surface;

FIG. 6 is a cross-section similar to FIG. 3 showing opposed heel slopesurfaces that may be provided by the present invention: and

FIG. 7 is a cross-section taken along line 7-7 of FIG. 3 showing arepositionable top cover providing for left and right mattress bolsters.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 1 , a hospital bed 10 or the like may provide foran articulating carriage 12 for supporting a mattress 14 thereupon. Thearticulating carriage 12 may provide, for example, multiple hingingsections 16 including a head section 16a, center section 16b, and footsection 16c, that may be angled to flex the mattress 14 to conform withthe sections 16, for example, to raise the head of the mattress 14 orlower the foot of the mattress 14. For this purpose, the mattress 14 mayflex to follow motion of the sections 16.

Referring now to FIG. 2 , the mattress 14, when unarticulated, maypresent a generally planar cushion having opposed broad surfacespresenting a soft face 18a on one side and a firm face 18b on an obverseside separated by a mattress thickness, for example, of five to eightinches. Each of the faces 18 extends along the mattress length 20 from ahead end 22 to a foot end 24, for example, any of 76, 80, and 84 inches,and extends along the mattress width 26 between left and right sides,for example, of any of 35, 39 and 42 inches. It will be appreciated thata variety of other dimensions may also be provided. The mattress 14 isgenerally sized to support a supine adult along its length (the mattresslength extending from head end 22 to foot end 24) on either of the softface 18a or firm face 18b when that face is horizontal and uppermost.

The soft face 18a may be labeled with a firmness designator 30 such asthe word “soft” or other similar phrase or symbol as well asmanufacturer information 31 visible when the soft face 18a is positionedon top. Conversely the firm face 18b may be labeled with a firmnessdesignator 30 such as the word “firm” or other similar phrase or symboltogether with manufacturer information 31 visible when the firm face 18bis positioned on top. An indication of the head of the mattress 14 maybe provided, for example, in the orientation of the firmness designators30 being positioned to be read while facing the head of the mattress 14or other designator (not shown). These firmness designators 30 may beapplied directly to the outer faces of the elastomeric foam describedbelow.

Referring now to FIG. 3 , the mattress 14 may be constructed frommultiple parallel laminated layers 32 and 34 each of an elastomeric foammaterial such as polyurethane foam. The foam layers 32 will generallyhave a width substantially equal to the width of the mattress 14 and athickness being a fraction of the thickness of the mattress 14 so thatthe number of layers 32 times their thickness equals the thickness ofthe mattress 14. The width may be reduced slightly when side bolsters 76are used as described below.

All but the outermost, softest of foam layers 32a will have a lengthslightly shorter than the length of the mattress 14 to extend from ahead end 22 of the mattress 14 to a point just short of the foot end 24of the mattress 14 where a patient's heels would rest. This length willgenerally be at least three quarters of the length of the mattress. Theoutermost, softest foam layer 32a may, in contrast, extend the fulllength of the mattress 14.

Foam layer 34 will have a width generally equal to the width of themattress 14 and a total thickness comparable to the thicknesses of thelayers 32 minus the softest, outermost foam layer 32a. The length offoam layer 34 will be such as to make up the difference between thelength of the inner foam layers 32 and the length of the mattress 14 andso that layer 34 is positioned primarily beneath the heel of the patientwhen the patient is resting on the mattress 14.

In one embodiment, as shown in FIGS. 3 and 4 , layers 32a-32d will beprovided assembled together by adhesive into a unitary mattress core.Specifically layer 32a may be positioned proximate to the soft face 18aand layer 32d may be positioned proximate to the firm face 18b. Layer32a may then have its inner broad surface attached to a first broadsurface of layer 32b with the second broad surface of layer 32b attachedto a first broad surface of layer 32c, and with the second broad surfaceof layer 32c attached to the inner broad surface of layer 32d.

Generally the layers 32 will each have a different firmness, forexample, as designated by an indentation force deflection number (IFD),for example, as measured by ASTM D3574 for a uniform volume of material(e.g., a 15″ by 15″ by 4″ foam slab). Preferably, layer 32a is softer(lower IFD number) than layer 32d and layer 32b will be softer thanlayer 32c. Layer 32b, on the other hand, will be harder than layer 32a,and layer 32c will be harder than layer 32d. Accordingly, a relativelyfirm middle layer, for example including layers 32b and 32c, which isnormally used on the bottom of medical mattresses, is placed in thecenter of the mattress 14. Positioning the firm layer in the middle ofmattress 14 allows both top and bottom sides of the mattress 14 toprovide improved weight capacity and pressure redistribution when usedon either face 18a or face 18b.

The layers 34 under the patient's heel will desirably each provide lowIFD values so as to reduce point pressures on the patient's heel. Thislayer may be of uniform IFD value, for example, comparable to layer 32a.

Layer 34 may be attached in a butt joint to the layers 32 by adhesive.

One possible selection of foam values for each layer is provided in thefollowing table:

TABLE I IFD for standard Thickness Section Layer test sample (inches)All 32a 7 1.5 Head and torso 32b 13 1.5 32c 75 1.0 32d 20 2.5 Heels 34 7 6.5 total

Referring still to FIG. 3 , the layers 32 and 34 when assembled may becovered by Nomex® or another fire resistant material 40 to provide aburn resistant “sock” which in turn may be covered by a stretchablefabric cover 42 possibly including waterproof qualities. This latterfabric cover 42 may provide for a zipper to allow it to be removed,cleaned, and then re-installed and includes the manufacturer information31 and firmness designator 30, described above, printed or embroideredon the outer surface. The cover 42 may, for example, be made of StaffordCPU 150 fabric, commercially available from Stafford Textiles Limited ofToronto, Canada, a stretchable fabric that reduces “hammocking” allowingbetter pressure redistribution.

Referring now to FIG. 4 , in one embodiment, cover 42 at the portionsextending over the sides of the mattress 14 may support hook and loopfastener strips 44 (for example Velcro®) running generally horizontallyalong the vertically extending left and right edges and head and footedges of the mattress 14 as stitched thereto. A bottom cover 46 havinggenerally a central rectangular panel equal in area to the area of thesoft face 18a or firm face 18b may have left and right extending flapsand headward and footward extending flaps 54 supporting mating hook andloop strips 55. In this way, the bottom cover 46 may be attached toeither cover the firm face 18b when the soft face 18a is facing upwardto be used by the patient, or to cover the soft face 18a when the farmface 18b is facing upward to be used by the patient, as held in place byinter-engagement of the strips 55 and 44. In either configuration of thebottom cover 46, an outwardly exposed surface of the panel 50 mayprovide for patches of slip resistant material 56 such as a rubber thatwill frictionally engage the sections 16 of the bed 10 (shown in FIG. 1) to hold the mattress 14 in place during articulation of the bed 10.

Referring now to FIG. 5 , in an alternative embodiment, cover 42 may beattached to one vertical edge (a right edge as shown) of each of tworightwardly extending fabric strips 60 seamed at one edge to the cover42 and having a length to be folded over or under the mattress 14 asindicated by arrows 62. When so folded, the fabric strips 60 mayreleasably attach to an opposite edge of the cover 42 by means of hookand loop fasteners 64 on the strips 60 and corresponding hook and loopfasteners 66 on imposed vertical edges of the cover 42. Both sides ofthe strips 60 may be coated with a nonskid material 68 such as rubber orthe like so that some nonskid material 68 is exposed in eitherorientation.

Referring now to FIG. 6 , the layers 32a and 34 beneath the patient'sheel 70 may be tapered to provide a downward slope 72 toward a foot end24 of the mattress 14 on the upper surface of the mattress 14 and anupward slope 74 mirroring that of downward slope of 72 on the undersurface of the mattress 14 so that in either orientation pressure on thepatient's heel against the mattress 14 is reduced in favor of pressureagainst a larger surface of the patient's calf.

Referring now to FIG. 7 , in one embodiment, the left and right edges ofthe foam layers 32 (and 34) may optionally abut side bolsters 76constructed of a high IFD foam, for example, having a value of 60. Theside bolsters 76 extend the full height and length of the mattress 14and have a thickness of approximately 2 to 3 inches to provide stiffelements at the side of the mattress 14 that tend to cradle the patientaway from the edges of the mattress 14. The side bolsters 76 may beattached to the other foam layers and positioned inside of the fabriccovering of the mattress 14.

An upper cover 80 may be constructed to be similar to the bottom cover46 and to provide for left and right and foot and head tabs 82 extendingaway from a center panel 84. Each of the tabs 82 may include a hook andloop strip 86 attaching to a corresponding hook and loop strip 88 on thevertical walls of the cover 42 to retain the panel 84 against an uppersurface of the mattress 14. Positioned on the left and right edge of thepanel 84 near the left and right edge of the mattress 14 may be upwardlyextending foam bolsters 90 that assist in retaining the patient centeredin the panel 84. The bolsters 90 may include a central foam element, forexample, having a high IFD of 75 and may extend upward by approximately5 inches. The bolsters 90 may be held against the upper surface of thepanel 84 by a fabric covering 92 attached by stitching to the remainderof the cover 80. In this way the bolsters 90 may be placed on either thesoft face 18a or the firm face 18b according to how the mattress 14 isoriented.

In either orientation of the mattress 14, having the soft face 18aupward or the firm face 18b upward, the mattress 14 may receive apatient to provide a pressure redistributing surface suitable forsleeping and moderating high-pressure points which may lead to pressureulcers or the like. The selection of the firmness of the exposed face ofthe mattress may be made according to a desire to control theconcentration of pressure on the surface of the user's body and/or toprovide for support of the patient in the particular posture, forexample, to alleviate back pain or the like. In addition, the firmnessof the exposed face of the mattress may be selected to control thetemperature of the interface between the patient's skin and themattress, with a firmer mattress, which is less enveloping, providing acooler interface.

In this regard, it will be appreciated that not only will differentusers prefer different firmnesses in the mattress, but that a singleindividual may wish to vary the firmness of the mattress at differenttimes. A single mattress offering two degrees of firmness provides asubstantial cost savings in both situations.

It will be appreciated that other polymer foams may be used in lieu ofpolyurethane foam including for example latex foams and so-called“memory foam”.

Certain terminology is used herein for purposes of reference only, andthus is not intended to be limiting. For example, terms such as “upper”,“lower”, “above”, and “below” refer to directions in the drawings towhich reference is made. Terms such as “front”, “back”, “rear”, “bottom”and “side”, describe the orientation of portions of the component withina consistent but arbitrary frame of reference which is made clear byreference to the text and the associated drawings describing thecomponent under discussion. Such terminology may include the wordsspecifically mentioned above, derivatives thereof, and words of similarimport. Similarly, the terms “first”, “second” and other such numericalterms referring to structures do not imply a sequence or order unlessclearly indicated by the context.

When introducing elements or features of the present disclosure and theexemplary embodiments, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of such elements orfeatures. The terms “comprising”, “including” and “having” are intendedto be inclusive and mean that there may be additional elements orfeatures other than those specifically noted. It is further to beunderstood that the method steps, processes, and operations describedherein are not to be construed as necessarily requiring theirperformance in the particular order discussed or illustrated, unlessspecifically identified as an order of performance. It is also to beunderstood that additional or alternative steps may be employed.

It is specifically intended that the present invention not be limited tothe embodiments and illustrations contained herein and the claims shouldbe understood to include modified forms of those embodiments includingportions of the embodiments and combinations of elements of differentembodiments as come within the scope of the following claims. All of thepublications described herein, including patents and non-patentpublications are hereby incorporated herein by reference in theirentireties.

What we claim is:
 1. A reversible, dual-firmness mattress comprising: amattress body having opposed first and second supporting surfaces eachsized and adapted to receive and support a supine individual extendingalong a mattress length when either of the first and second supportingsurfaces is upwardly facing and horizontal, the mattress body includingat least three polymer foam layers each having a different firmness andextending along substantial portions of the mattress length, a firmnessof the polymer foam layers selected to present presenting a lesserfirmness to a supported individual lying on the first supporting surfacethan to the supported individual lying on the second supporting surface;and a cover fitting around the mattress body to retain the mattress bodytherein; wherein a first polymer foam layer adjacent to the firstsupporting surface has a lesser indentation force deflection (IFD) thanthe polymer foam layer adjacent to the second supporting surface and athird polymer foam layer positioned between the first and second polymerfoam layers and having an IFD greater than the IFD of the first polymerfoam layer and the second polymer foam layer wherein a first polymerfoam layer that defines a core layer as positioned between a second andthird polymer foam layers has an indentation force deflection (IFD)greater than either of the second and third polymer foam layers andwherein the at least three polymer foam layers are adhered together sothat the mattress body is unitary; and wherein the second polymer foamlayer has a lesser IFD than the third polymer foam layer.
 2. Thereversible, dual-firmness mattress of claim 1 further including a fourthpolymer foam layer positioned between the first second and third polymerfoam layers having a greater IFD than the first at least one of thesecond and third polymer foam layer layers and a lesser IFD than thenthe third first polymer foam layer.
 3. The reversible, dual-firmnessmattress of claim 1 wherein at least some of the polymer foam layers donot extend over a foot portion of the mattress length, the foot portionadapted to support feet of the supine individual; and including at leastone foot region polymer foam element extending along the mattress lengthin the foot portion having firmness no more than a least firmness of thedifferent polymer foam layers outside of the foot portion.
 4. Thereversible, dual-firmness mattress of claim 3 wherein the foot regionpolymer foam element has a uniform firmness.
 5. The reversible,dual-firmness mattress of claim 3 wherein the foot region provides areduced mattress thickness tapering inward to an end of the mattress. 6.The reversible, dual-firmness mattress of claim 1 providing opposed leftand right bolsters of polymer foam having an firmness no less thanoutermost of the polymer foam layers, the left and right bolstersextending along a left and right edge of the mattress and attached tothe polymer foam layers.
 7. The reversible, dual-firmness mattress ofclaim 1 further including a second cover outside the first cover whereinthe second cover includes indicia indicating relative firmness of thefirst and second opposed surfaces; and wherein the first cover andsecond cover cover the substantial entirety of the polymer foam layers.8. The reversible, dual-firmness mattress of claim 1 wherein the firstand second opposed surfaces are substantially planar without aconvoluted surface.
 9. A reversible, dual-firmness mattress comprising:a mattress body having opposed a first supporting surface generallydisposed in a first plane and an opposed second supporting surfacessurface generally disposed in a second plane different than the firstplane, one of the first or second supporting surfaces overlying theopposed first or second supporting surface when either of the first orsecond supporting surfaces is upwardly facing and horizontal, each ofthe first and second supporting surfaces sized and adapted to receiveand support a supine individual extending along a mattress length wheneither of the first and second supporting surfaces is upwardly facingand horizontal, the first supporting surface comprising a firstplurality of outer edges generally disposed within the first plane andthe second supporting surface comprising a second plurality of outeredges generally disposed within the second plane that are eachindividually coplanar with at least one of the outer edges in the firstplurality of outer edges, the mattress body including at least threepolymer foam layers each having a different firmness and extending alongsubstantial portions of the mattress length, a firmness of the polymerfoam layers selected to present a lesser firmness to a supportedindividual lying on the first supporting surface than to the supportedindividual lying on the second supporting surface; and a cover fittingaround the mattress body to retain the mattress body therein; themattress further including a bottom cover adjustable to be positionedover at least a portion of the bottom of the mattress when the mattressis in either of two orientations with the opposed first or secondsupporting surface uppermost, the bottom cover including outwardlyexposed anti-slip material.
 10. The reversible, dual-firmness mattressof claim 9 wherein the bottom cover is permanently attached to a thecover fully surrounding fitting around the mattress body at one edge ofthe bottom cover and releasably attachable to the cover fullysurrounding fitting around the mattress body at an opposed edge of thebottom cover.
 11. The reversible, dual-firmness mattress of claim 10wherein the first and second surfaces are not convoluted.
 12. Thereversible, dual-firmness mattress of claim 9 wherein the bottom coveris releasably attachable to a mattress the cover with hook and loopfasteners.
 13. A reversible, dual-firmness mattress comprising: amattress body having opposed a first supporting surface generallydisposed in a first plane and an opposed second supporting surfacessurface generally disposed in a second plane different than the firstplane, each of the first and second supporting surfaces sized andadapted to receive and support a supine individual extending along amattress length when either of the first and second supporting surfacesis upwardly facing and horizontal, one of the first or second supportingsurfaces vertically overlying the opposed first or second supportingsurface when either of the first or second supporting surfaces isupwardly facing and horizontal, the mattress body including at leastthree polymer foam layers each having a different firmness and extendingalong substantial portions of the mattress length, a firmness of thepolymer foam layers selected to present a lesser firmness to a supportedindividual lying on the first supporting surface than to the supportedindividual lying on the second supporting surface; and a cover fittingaround the mattress body to retain the mattress body therein; themattress further including a top cover adjustable to be positioned overat least a portion of the top of the mattress body when the mattressbody is in either of two orientations with the opposed first or secondsupporting surface uppermost, the top cover providing upwardly extendingbolsters positionable at opposed left and right edges of the mattressbody.
 14. The reversible, dual-firmness mattress of claim 13 wherein thetop cover is releasably attachable to a the cover of fitting around themattress body with hook and loop fasteners.
 15. The mattress of claim 13wherein the polymer foam is a polyurethane foam.
 16. A reversible,dual-firmness mattress comprising: a mattress body having at least threelayers of polymer foam material of different indentation forcedeflection (IFD) values and adhered together so that the mattress bodyis unitary, the layers of polymer foam material extending generallyparallel to opposed first and second support surfaces of the mattressand presenting a lesser firmness to a supported individual lying on thefirst support surface that is generally disposed in a first plane thanto the supported individual lying on the second support surface that isgenerally disposed in a second plane different than the first plane,wherein one of the first or second supporting surfaces overlies theopposed first or second supporting surface when either of the first orsecond supporting surfaces is upwardly facing and horizontal, the volumeweighted IFD values in a half of the mattress closest to the firstsupport surface being lower than volume weighted IFD values in a half ofthe mattress closest to the second support surface; wherein the firstsupporting surface comprises a first plurality of outer edges generallydisposed within the first plane and the second supporting surfacecomprises a second plurality of outer edges generally disposed withinthe second plane that are each individually coplanar with at least oneof the outer edges in the first plurality of outer edges; and a fabriccover surrounding the mattress body.
 17. A reversible, dual-firmnessmattress comprising: a mattress body having an opposed first supportingsurface generally disposed in a first plane and an opposed secondsupporting surfaces surface generally disposed in a second planedifferent than the first plane, each of the first and second supportingsurface sized and adapted to receive and support a supine individualwhen the surface is upwardly facing and horizontal, an wherein one ofthe first or second supporting surfaces overlies the opposed first orsecond supporting surface when either of the first and second supportingsurfaces is upwardly facing and horizontal, wherein the first supportingsurface comprises a first plurality of outer edges generally disposedwithin the first plane and the second supporting surface comprises asecond plurality of outer edges generally disposed within the secondplane that are each individually coplanar with at least one of the outeredges in the first plurality of outer edges, and a firmness of the firstand second supporting surfaces selected to present a greater firmness toa supported individual lying on the first supporting surface than to thesupported individual lying on the second supporting surface; an innercover fitting around the mattress body to retain the mattress bodytherein; and an outer cover removably positionable over the inner coverto present a slip resistant surface at a bottom of the mattress body andnot at a top of the mattress body; and wherein the inner cover and outercover the a substantial entirety of the polymer foam layers mattressbody.
 18. A reversible, dual-firmness mattress comprising: a mattressbody having at least three layers of polymer foam material adheredtogether so that the mattress body is unitary, the at least three layersextending generally parallel to opposed and overlying first and secondsupport surfaces of the mattress when either of the first and secondsupporting surfaces is upwardly facing and horizontal, the firstsupporting surface generally disposed within a first plane andcomprising a plurality of first supporting surface sides disposed withinthe first plane, and the second supporting surface generally disposedwithin a second plane different than the first plane and comprising aplurality of second supporting surface sides disposed within the secondplane that are each individually coplanar with a corresponding firstsupporting surface side, the layers presenting a lesser firmness to asupported individual lying on the first support surface than to thesupported individual lying on the second support surface, each of thelayers having an indention force deflection (IFD) value such that thetotal of the IFD values of each given layer or portion thereof locatedin a first half of the mattress nearest the first support surface timesa thickness of the respective given layer or portion thereof located inthe first half of the mattress is less than a total of the IFD values ofeach given layer or portion thereof located in a second half of themattress nearest the second support surface times a thickness of therespective given layer or portion thereof located in the second half ofthe mattress; a cover surrounding the mattress body; and wherein a firstlayer positioned between a second and third layer of the at least threelayers has an IFD value greater than the other two layers.
 19. Thereversible, dual-firmness mattress of claim 18 including indiciaindicating relative presented firmness of the first and second supportsurfaces and attached to the reversible, dual firmness mattress.
 20. Thereversible, dual-firmness mattress of claim 18 further including afourth layer positioned between the second and third layers and having agreater IFD value than a closest of second and third layers and a lesserIFD value then the first layer.
 21. The reversible, dual-firmnessmattress of claim 18 wherein the mattress body is free from rigidelements that would prevent flexure of the mattress body along itslength.
 22. The reversible, dual-firmness mattress of claim 18 whereinat least one layer is memory foam.
 23. The reversible, dual-firmnessmattress of claim 18 wherein at least three layers of polymer foammaterial have different thicknesses.
 24. The reversible, dual-firmnessmattress of claim 18 wherein the first layer has an IFD value at leasttwice that of at least one of the second and third layer.
 25. Thereversible, dual-firmness mattress of claim 24 wherein one of the secondand third layers has an IFD value at least one and a half times the IFDvalue other of the second and third layers.
 26. The reversible,dual-firmness mattress of claim 18 wherein the at least three layers ofpolymer foam material are adhered together by adhesive.
 27. Areversible, dual-firmness mattress comprising: a mattress body having atleast three layers of polymer foam material adhered together so that themattress body is unitary, the at least three layers extending generallyparallel to opposed first and second support surfaces of the mattress,the layers presenting a lesser firmness to a supported individual lyingon the first support surface than to the supported individual lying onthe second support surface, each of the layers having an indention forcedeflection (IFD) value such that the total of the IFD values of eachgiven layer or portion thereof located in a first half of the mattressnearest the first support surface times a thickness of the respectivegiven layer or portion thereof located in the first half of the mattressis less than a total of the IFD values of each given layer or portionthereof located in a second half of the mattress nearest the secondsupport surface times a thickness of the respective given layer orportion thereof located in the second half of the mattress; a coversurrounding the mattress body; and wherein a first layer positionedbetween a second and third layer of the at least three layers has an IFDvalue greater than the other two layers, and wherein IFD values of eachlayer decrease progressively without increasing from a center of themattress halfway between the first and second support surfaces to thefirst and second support surfaces.
 28. A reversible, dual-firmnessmattress comprising: a mattress body having at least three layers ofpolymer foam material adhered together so that the mattress body isunitary, the at least three layers extending generally parallel toopposed first and second support surfaces of the mattress, the layerspresenting a lesser firmness to a supported individual lying on thefirst support surface than to the supported individual lying on thesecond support surface, each of the layers having an indention forcedeflection (IFD) value such that the total of the IFD values of eachgiven layer or portion thereof located in a first half of the mattressnearest the first support surface times a thickness of the respectivegiven layer or portion thereof located in the first half of the mattressis less than a total of the IFD values of each given layer or portionthereof located in a second half of the mattress nearest the secondsupport surface times a thickness of the respective given layer orportion thereof located in the second half of the mattress; a coversurrounding the mattress body, wherein a first layer positioned betweena second and third layer of the at least three layers has an IFD valuegreater than the other two layers, and, wherein each of the layers hasan IFD value such that the total of the IFD values of each given layeror portion thereof located in a first half of the mattress nearest thefirst support surface times a thickness of the respective given layer orportion thereof located in the first half of the mattress is at least50% less than the total of the IFD values of each given layer or portionthereof located in a second half of the mattress nearest the secondsupport surface times a thickness of the respective given layer orportion thereof located in the second half of the mattress.
 29. Areversible, dual-firmness mattress comprising: a mattress body having atleast three layers of polymer foam material adhered together so that themattress body is unitary and adapted to flex along its length, the atleast three layers extending generally parallel to opposed first andsecond support surfaces of the mattress, the layers adapted to present alesser firmness to a supported individual lying on the first supportsurface than to the supported individual lying on the second supportsurface, each of the layers having an indention force deflection (IFD)value such that the total of the IFD values of each given layer orportion thereof located in a first half of the mattress nearest thefirst support surface times a thickness of the respective given layer orportion thereof located in the first half of the mattress is less than atotal of the IFD values of each given layer or portion thereof locatedin a second half of the mattress nearest the second support surfacetimes a thickness of the respective given layer or portion thereoflocated in the second half of the mattress; and a cover surrounding themattress body; wherein a first layer positioned between other two layershas an IFD value greater than the other two layer; and further includingindicia indicating relative firmness of the first and second supportsurfaces attached to the reversible, dual firmness mattress.
 30. Thereversible, dual-firmness mattress of claim 1, wherein the mattress isadapted to flex to conform to an articulating bed carriage when eitherof the first and second supporting surfaces are positioned on thearticulating bed carriage.
 31. The reversible, dual-firmness mattress ofclaim 16, wherein the mattress is adapted to flex to conform to anarticulating bed carriage when either of the first and second supportsurfaces are positioned on the articulating bed carriage.
 32. Thereversible, dual-firmness mattress of claim 1, wherein one of the layerscomprises a first and second component layer.